Pellucid composition and method for coating foodstuffs and articles thereby obtained



June 24, 1958 J. R. wlR PELLUCID COMPOSITION ANO METHOOAFOR OOAIINGFOons'rUFFs AND ARTIOLES THEREBY OBTAINED Filed Jan. 2s, 1956 T E'rAl. Iv 2,840,474

INVENTORS. James A. W/rr Haro/d6. e//y Ric/70m M Krajeu/.s/fl' HTTORNEYS Ysanction!) coMPosrrroN METHoD" lson coATINoFooDsTUFFs AND ARTI- cansTHEREBY yorArNED .lames R. Wirt, Harold C. Kelly, and .Richard M.Kraiewsisi, Midland, Mich., assignors to The Dowhemical Company,Midland, Mich., a corporation of Delaware Application January 23, 41956,Serial No. 560,608 Claims. :(Cl. 99-166) This invention relatestocoating compositions comprising cellulose ethers which arey especiallylsuited for enveloping certain articles of food, particularlykmeat andmeat products, in transparent, tightly-adhering protective coatingswhich may readily be s'trippedor peeled from. the article. Moreparticularly,` it lis yconcerned with such a coating compositionwhich-is appliedr'from the molten condition. -In order to .avoidsesquipedalian and cumbrous expressions, compositions of this nature arefrequently referred to as hot melts andv willbe characterized by -suchterm in the following description and specification. The yinventionalsohas reference to a method for coating food articles vwith suchcompositions and to coated articles thereby obtained.

It would [be advantageous to `provide certain, articles of food,particularly meat and meat products, with, tough,

oxidation, dehydration -or contamination Ain the coated foodstuff; and,as a primary requirement, absolute'nontoxicity, i. e., freedom from anytendency to transfer harmful materials to the foodstuff. -I-twouldbehighly desirable for such coatings `to.be obtainablefrmfreadlilyavailable and inexpensive materials and tojbe lutilizable in aconvenient andeconomic manner. f

These and other desirable advantages and .benefits may be derived with rthe coating composition of the present invention which is comprised of,a mixture consistingfessentially of between about 19 and y28andpreferably hejtween 21 and 24 parts :by weight .of ethyl cellulose;be-

tween about 39 and 7 3:5v and preferably'between 55 :and

68 parts by vweight Aof 1a "refined mineral oil; notimore than about 5.0and preferablyv between rl0.7 .and,2.l3 @parts Y by weight of aplasticizer selectedfrom .the group yof plasticizers consisting ofglycerol monooleate, lnfbutyl stearate, glycerol monostearate'andmixtures thereof;V not more than about 5.0 and preferably between'Or-7and .2.8 parts by weight of acetylated `mono-glyceride; between about7.0 and 20.0 and preferably between`9.'2 'and 14-.6 parts by weight ofcastor oil; and, optionally and advantageously, between about 0.5Vlant1-3.`() v'and preferably between 1.5 and 2.0 parts byzweightof'a-suitable nontoxic antioxidant material` for the fethylcellulose. iItis desirable for-a total of about 100` partsby weight-ofall the ingredients to be present in thefformulated composition. u 51 fThe improved compositions of .thepre'sent'iinvention ordinarily formmolten mixtures attemperaturesinzexcess nited States Patent Pfte'ntedJune 24, 1958 `2. of the boiling point of water. any desired manner toarticles which ymay b'e v:atf vany temperature Vbeneath that of thehotmelt. v Advantageously, particularlywhen fresh meat vor'meat productsare involved, the' coatingV composition may -be applied by aV methodwhich 4comprises freezing the article, or at least the surface of thearticle, -of foodfto'be coated; and coatingv the frozen article with themolten composition.V Such `a method 'isk beneficial in that thesurface-of the articlebeing coated, particularly meats and the Alike, isless likely to attain discoloring vtemperatures and those causing'vaporization of surface juices. While brushing, sprayingand othertechniques 'may be employed in order to apply the coatingcomposition tothe article, it Ais frequently more expedient to employ dip coatingtechniques for this purpose `wherein the article is dipped in the moltencomposition to effect the coating pick up," after which it is withdrawnandth'e applied coating composition permitted to 'cool' and harden.`

Coated articles of food, particularly meats, accord-V ance with thepresent invention have a' highl'yattractive and exceptionally'pleasin'gappearance. The coating 'has absoluteV transparencyv over a yWidetemperature range, even at temperatures vas low as those in theneighborhood of about 20 F. and lower. This desirable feature permits aready visual inspection and evaluation to be made of the *coatedfoodstuff. The coating is not sticky, oily, greasy or otherwise`uncomfortable to touch or handle.` It adheres tightly as a thin, limpidaboutA the article andv conforms .closely to its contours, even whenbony 'meats orfowl are involved. It is nontoxic and odorlessland doesnot impart odors `or tastes to the food which is coated. It isIeadi1y`peelable, ,cuttable or s'trippable ina clean and eicient mannerfrom thearticle .of food and 'does not .require washing orother Atediousand inconvenient procedures for itsV complete @removal. l'In addition,,the coating isrelatively exibleat temperatures as low as about 0 F. sot-hatvitresists damage. due to handling and storage of a coated articlebeing maintained in a frozen condition; It alsol has an extremely 'lowrate ofgas and water vapor transmission, comparable tofthose whicharefoundv in other distinct varieties of ethyl cellulose` type coatings,.so that the coated articles may be preserved -in a better .conditionand are` less susceptible to becoming. rancid or dehydrated orto developfreezer burn. In addition, the coating compositionI of the present`invention effectively prevents the absorption of .undesirable foreignodors an tastesin the foodrproduct. The ethyl cellulose which may beemployed in `the practice of the `present invention ,is a commonlyavailable material having an ethoxylcontent inthe range from about 47.5to about SOpercent by weight.Y It shouldhave alow viscosity of less thanabout 30 centipoises, las determined in ya solution of about 5 .percentby weight of theethyl-fc'ellulose in a solvent mixtureconsisting ofabout 8.0 parts by volume of ltoluene :and about .20 parts .by

' volume vof ethanol. yIt is beneficial toemploy a cellulose etherhaving Va viscosity in :the `neighborhood fof 6-11 centipoises. Y f' fThe refined oilmayladvantageously bea'imineralfoil of y.aparailinic-variety orfit may be derived .fromanaphtheme-petroleumsource. vIt is desirable forlight colored or Water white oils to`beernployed.Y Oils havingaviscosityv-in therange from -aboutO to `about400 Sayholt units at areordinarily preferable.

Advantageously, glycerol mono-oleate ,is utilizedftas one .of theplasticizer'ingredients. inthe .compositions of the invention from theAgroup of ,-plasticizers consisting .of

glycerol tnnono-oleate, n-.butyl.,stearate,.fg1ycero1 lmono- A 1stearatefandl-mixtures.thereof. Y 1:

They may be applied in l'lfheacetylated mono-glyceride incorporated inthe compositions of the present invention is a derived fat in whichacetic acid isone of thefatty acids present. Advantageously theacetylated mono-glyceride `may be derivedjufrnmdard for`, hydr ogenatedlard and containsan averageof t 'l east oneacetic Aacid groupand onelong chaiuafatty.- acid group; per fat molecule.. Preferably theacetylated mono-glyceride which `is employed contains Wb. ascii?idsrups. andone. lons hain fattycid group `for eachfmat molecule whichis present.

trade-name Myverol No. 70;` about 1.40 percent by weight of acetylatedmono-glyceride which was obtained under the trade-name Myvacet 9-40;about 11.50 percent by weight of a refined and deodorized castor oil,which was obtained under the trade-name Crystal O Castor Oil; and, as anantioxidant, about 1.0 part by weight-of butylated hydroxy toluene,which was obtained under the' trade-name Tenox BHT. After the dipping,

the coating was allowed -to cool and harden. All of the tates retentionof the clear lucid characteristics of the 1 In reparing'thehotmeltcoating compositions of the presentginvention', caregshould be`takeu to selectsuch reltivefproportions 'of lingredients asl fwill`produce av coating having optirnuwcharacteristics. Thus, in somecombinations ofl ir'lgedients," a; larger proportion ofthe.tliiltluleiey-iir0du9e @are fissgvshot melt than isidesirablefortpartculrar operating temperatures whereas smaller'proportions, .insome instances, may not lend sufficient strengthtdthe film coating...ySimilarly,l greater amounts of oilmay sometimes tend'to yield an oilyfilm coating. On the `otherfhand. smaller amounts of oil may sometimesincrease` the viscosity of the hot melt beyond frnore desirable.,degree'sf, A`In lan analogou's. manner, too great a proportionofftheplasticizing ingredients may"a`t times produce la film-coatingwhich is softer and more loily than might be otherwise obtained ,whiletoo little use of suchingredientsmay. incertain instances, impartundesirablefu brittle characteristics to the film' coating.-

ASince the hot'melt compositions of the present invention areatlrelativclyhigh temperatures duringV their ap'- plication`,` `it` isadvantageous to coat many articles while they` are in affrozencondition.This minimizes the possi bility of causingfslightsurface discolorationand dehydra- 'tion'pf the lfoodstuff;"particularly when meatandl meat:productsfarebeingcoatedfandobviates any objections 'R to the coatedarticles which may arise for" such reasons.

`The discolorations which mayoccur from coating food articles whileVthey are at normal temperatures are. in-

I tciciioifis,` h'o wever, and bearf no relationship to their r qualityor` wholesomene'ss" in any `consideration 'other than i'appeiatrance.`Thus'gif itis suitable, food articles which are not ina frozen condition'may be coated satisfactorily with the composition'ofthe presentinvention.

4"In many instancesthere may be no `significant advanu tage to chillingor freezing the article' before coating. This may be the case,forexamplqwhen various smoked or cured meats,jfsh ortvfowll are beingcoated.V 'I'he normalgtreated appeararlccfofA such foodstuffsisacceptable and does` not detrctfr'orn Vtheir marketability.

By way Vof illustration, vvarious cuts of meat, including A i steaks,lchops and roastsgfrom beef, lamb and pork were coated by firstfreezingrthem land then dip coating `them witha hot melt at about` 320`F. which was comprised cent by` weight* of i a refined mineral i doil fmixture which consisted V`of equal weightproportions of a` refinedmineral group per `fat molecule, which `was obtained under the of about23.0 percent vby" weightlof an ethyl celluloscpf y t a `viscosity gradeof aboutjl0 centipoises, which was obj tained underthe trade-nameEthocel; about-bltlperoilhaving viscositybetwum about' 345 and 355Saybolt coated articles, as schematically illustrated in a perspectiveview in Figure 1 and in cross-section in Figure 2 of the accompanyingdrawing, had an attractive, sparkling and pleasing appearance and werenot objectionable to the touch. The applied coating adhered tightly tocach of the articles and conformed closely to them as a very thin,enveloping -flrn about their various irregular contours. The coating hadabsolute clarity, allowing normal andunimpaired visual inspection of thecoated articles which retained.l their essentialnatural appearances. Thecoating was tough [and did not become embrittlcd atfreezingtemperatures. It could be stripped cleanly from the articleswithout remnants or segments of the coating adhering touthe'foodstui,permitting the articles to be obtained in their normallyavailablecondition after being freed of the coating. In addition, the coatingprovided apparently indefinite Aprotection against freezer burn whentheaarticles` were maintained in a `frozen condition fork long p eriodsof time. a

Equivalent Ygood results are similarly obtainable with poultry if careis taken to suitably plug or cover the cavities in their dressedcarcasses.A Various cheeses may also be coated satisfactorily withhotmelt compositions similar to the foregoing.

What is claimed is:

l. Transparent "coating composition for articles of food which consistsof a mixture, adapted to be applied as ahot 'meltfof between about 19.0land 28.0 parts 'by weight of anethyl cellulosehaving an ethoxyl contentbetween about 47.5 I:and 50 percent by weight and a viscosity `less thanabout 30 centipoises, as determined inra 51 percent by vweight solutionthereof in an 80:20 mixture, by volume, of toluene and ethanol; betweenabout 39.0 and 73.5 parts by weight of a refined mineral loil having `aSayboltviscosity-at 100 F. between about and 400 units; not more thanabout 5.0 parts by'weight of a plasticizer selected fromthe group. ofplasticizers consisting j'of glycerolI monooleate, n-butylV stearate,glycerol "rnonostearate,` and mixtures thereof;l not more than`about}f`-50 parts"y by weight of acetylarted monoglyceride; and betweenabout 7.0 and 20.0 Vparts by weight of castor oil;Y a v 2. 'Transparent41'coating `composition for articles of food `which consists'of amixture, adaptedto beapplied asa' hot' melt, of betweenabout 19.0 and28.0 parts by weight of an ethylrcellulose having an ethoxyl contentbetween` about `47.5 and 50 percent by weight and a viscosity'less thanabout 30 centipoises, as determined in a'5 percent-by weight solutionthereof `in an 80:20

mixture, by volume, of. toluene and ethanol; between about 39.0 and`73.5 parts by` weight of a refined mineral oil having a Sayboltviscosity at F. between about 80 and 4004 units; `not .more than about5.0 parts by weight of a plasticizer selected from the group ofplasticizers "consisting of glycerol mono-oleate, n-butyl stearate,'glycerolfmonostearate and mixtures thereof; not more` than Aabout 5.0parts by weight of acetylated monoglycerideybetween about `7.0 and 20.0parts by weight `of lcastor oil; and between about 0.5 and 3.0 parts byeweighty of" a non-toxic antioxidant material fonjthehethylf,cellulosejBI'Trarisparentgcoating composition for articles of food whichconsistsof a mixture, adapted to be applied as a hot melt, of between about 21.0and 24.0 parts byA weight ...of ,an *ethyl cellulose having an ethoxylcontent'between about 47.5 and `50 percent by weight and a viscosity inthe neighborhood of about 6-11 centipoises, as determined in a 5 percentby weight solution thereof .in an 80:20 mixture, by volume, of tolueneand ethanol; between about 55 and 68 parts by Weight of a refinedmineral oil having a Saybolt viscosity at 100 F. between about 80 and400 units; between about 0.7 and 2.8 parts by weight of a plasticizerselected from the group of pasticizers consisting of glycerolmono-oleate, n-butyl stearate, glycerol mono` stearate, and mixturesthereof; between about 0.7 and 2.8 parts by weight of acetylatedmono-glyceride; between about 9.2 and 14.6 parts by weight of castoroil; and between about 1.5 and 2.0 parts by weight of a non-toxicantioxidant material for the ethyl cellulose.

4. The composition of claim 3 wherein glycerol monooleate is theplasticizer selected from the group of plasticizers consisting ofglycerol mono-oleate, n-butyl stearate, glycerol monostearate andmixtures thereof. Y

5. The composition of claim 3 wherein the glycerol mono-oleate isderived from lard and contains an average of two acetic acid groups andone long chain fatty acid group per fat molecule.

6. The composition of claim 3 wherein the non-toxic antioxidant materialfor the ethyl cellulose is butylated hydroxy toluene.

7. Method for coating articles of food which comprises applying to thearticle, while it is being maintained at a relatively low temperature, athin, enveloping film of a coating from a composition in moltenvformconsisting of between about 19.0 and 28.0 parts by weight of an ethylcellulose having an ethoxyl content between about 47.5 and 50 percent byweight and a viscosity less than about 30 centipoises, as determined ina 5 percent by weight solution thereof in an 80:20 mixture, by volume,of toluene and ethanol; between about 39.0 and 73.5 parts by weight of arened mineral oil having a Saybolt viscosity at 100 F. between about 80and 400 units; not more than about 5.0 parts by weight of a plasticizerselected from the group of plasticizers consisting of glycerolmono-oleate, n-butyl stearate, glycerol monostearate, and mixturesthereof; not more than about rfrom a composition in molten formconsisting of between about 21.0 and 24.0 parts by weight of an ethylcellulose having an ethoxyl content between about 47.5 and percent byweight and a viscosity in the neighborhood of about -ll-centipoises, asdetermined in a 5 percent by Weight solution thereof in an. :20 mixture,by volume, of toluene and ethanol; between about`55 and 68 parts byweight of a rened mineral oil having a Saybolt viscosity at F. betweenabout 0.7 and 2.8 parts by weight of a plasticizer selected from thegroup of plasticizers consisting of glycerol mono-oleate, n-butylstearate, glycerol monostearate, and mixtures thereof; be-

tween about 0.7 and 2.8 parts by weight of acetylated` mono-glyceride;between about 9.2 and 14.6 parts by weight of castor oil; and betweenabout 1.5 and 2.0 parts by Weight of a non-toxic antioxidant materialfor the ethyl cellulose; and cooling the applied coating on the articleto a hardened condition.

9. The method of claim 8 wherein the composition is applied to thefrozen article by dip coating.

10. A coated food article as produced by the method of claim 7.

References Cited in the le of this patent UNITED STATESy PATENTS2,082,592 Nollau June 1, 1937 2,349,134 Bradshaw May 16, 1944 2,373,278Traylor Apr. 10, 1945' 2,551,463. Ramsbottom May 1, 1951 2,558,042 YCornwell June 26, 1951 2,577,211 Scharf Dec. 4, 1951 2,682,475 Smith Iune 29, 1954

1. TRANSPARENT COATING COMPOSITION FOR ARTICLES OF FOOD WHICH CONSISTSOF A MIXTURE, ADAPTED TO BE APPLIED AS A HOT MELT OF BETWEEN ABOUT 19.0AND 28.0 PARTS BY WEIGHT OF AN ETHYL CELLULOSE HAVING AN ETHOXYL CONTENTBETWEEN ABOUT 47.5 AND 50 PERCENT BY WEIGHT AND A VISCOSITY LESS THANABOUT 30 CENTIPOISES, AS DETERMINED IN A 5 PERCENT BY WEIGHT SOLUTIONTHEREOF IN AN 80:20 MIXTURE, BY VOLUME, OF TOLUENE AND ETHANOL, BETWEENABOUT 39.0 AND 73.5 PARTS BY WEIGHT OF A REFINED MINERAL OIL HAVING ASAYBOLT VISCOSITY OF 100*F. BETWEEN ABOUT 80 AND 400 UNITS, NOT MORETHAN ABOUT 5.0 PARTS BY WEIGHT OF A PLASTICIZER SELECTED FROM THE GROUPOF PLASTICIZERS